The instant invention relates to a compartment for powder coating of workpieces, comprising a floor, two sidewalls, two end walls at least one of which has a door opening for entry and/or exit of the workpieces, a ceiling, and a suction system outside of the compartment.
Workpieces usually are introduced into such compartments by a conveyor means and then coated with powder. Not all the powder supplied by the applicator devices to the workpieces actually deposits on the workpieces. Instead, the major part of this so-called excess powder settles on the compartment floor.
It is known to remove excess powder from the compartment by constructing the lower part of the compartment of sidewalls which are inclined in V shape with respect to each other, with a suction aperture provided at the lowest point thereof through which the powder slipping down along the oblique sidewalls is sucked off by means of a fan. As it is not possible to walk into such a compartment it is very difficult to clean it. Manual cleaning, especially of the suction channel disposed below the suction aperture practically is excluded (see for example, EP200681B1).
To overcome that, it has been proposed to design the floor of the compartment as a walkable discharge belt by which the accumulated excess powder is conveyed to a suction aperture at the end wall. Slots are provided at either side of the discharge belt outside of the two lower corner regions of the compartment and these slots communicate with lateral suction channels for recovery of the powder which a cleaning device blows off the walls of the compartment (see, for example, EP727 258B1). True, the floor constituted by the discharge belt is walkable and the walls of the compartment can be cleaned by a pneumatic cleaning device which is specifically provided for this purpose and movable through the compartment. But access to the suction channels located outside of the compartment for manual or mechanical cleaning is difficult. The discharge belt must be cleaned separately outside of the compartment. All this leads to an expensive structure.
It is an object of the invention to provide a compartment of the kind specified initially which is simple in structure, permits perfect removal of excess powder by suction and is easy to clean, including the suction channel.
A compartment according to the invention has a walkable floor embodied either by a stationary plate or a discharge belt. At least one but preferably two suction channels are integrated in the two lower corner regions of the compartment by the oblique walls according to the invention. These oblique walls preferably are hingedly connected to the inside surfaces of the sidewalls so that, for cleaning, they either can be tilted against the vertical inside surfaces of the sidewalls or removed from the same. Moreover, the pivotable connection of the oblique walls at the inside surfaces of the sidewalls permits easy adjustment of the gap widths of the suction gaps which are defined between the lower edges of the oblique walls and the floor of the compartment.
In the case of the embodiment where the floor of the compartment is a discharge belt, any remaining excess powder not sucked off laterally is conveyed out of the compartment and separately removed by suction outside of the same.
A compartment according to the invention is very cost effective due to its simple structure and the infrequent need for uncomplicated cleaning. The invention can be applied with particular advantage also where compartments are long.
Further advantageous modifications of the invention are covered by the dependent claims.